U.S. patent application number 11/459036 was filed with the patent office on 2007-03-01 for compression device for the limb.
This patent application is currently assigned to BRISTOL-MYERS SQUIBB COMPANY. Invention is credited to Simon Mark Adams, Wayne Lee Bonnefin, Mats Christiansson, Jose Arsenio Fernandez, David Geoffrey Wild.
Application Number | 20070049853 11/459036 |
Document ID | / |
Family ID | 34976355 |
Filed Date | 2007-03-01 |
United States Patent
Application |
20070049853 |
Kind Code |
A1 |
Adams; Simon Mark ; et
al. |
March 1, 2007 |
COMPRESSION DEVICE FOR THE LIMB
Abstract
A compression device for a limb of a patient comprises an
inflatable sleeve arranged to surround the limb and a conduit
attached to the sleeve arranged to deliver fluid to the sleeve. The
compression device also comprises a control system arranged to
control fluid flow in the device and a memory arranged to store
gathered data relating to use of the device.
Inventors: |
Adams; Simon Mark;
(Flintshire, GB) ; Fernandez; Jose Arsenio;
(Bridgend, GB) ; Christiansson; Mats; (Goteborg,
SE) ; Bonnefin; Wayne Lee; (Chester, GB) ;
Wild; David Geoffrey; (Wirral, GB) |
Correspondence
Address: |
BRISTOL-MYERS SQUIBB COMPANY
100 HEADQUARTERS PARK DRIVE
SKILLMAN
NJ
08558
US
|
Assignee: |
BRISTOL-MYERS SQUIBB
COMPANY
New York
NY
|
Family ID: |
34976355 |
Appl. No.: |
11/459036 |
Filed: |
July 21, 2006 |
Current U.S.
Class: |
601/151 ;
601/148; 601/149; 601/DIG.20 |
Current CPC
Class: |
Y10S 601/20 20130101;
A61H 2205/10 20130101; A61H 9/0078 20130101 |
Class at
Publication: |
601/151 ;
601/148; 601/149; 601/DIG.020 |
International
Class: |
A61H 9/00 20070101
A61H009/00 |
Foreign Application Data
Date |
Code |
Application Number |
Jul 21, 2005 |
GB |
0515040.4 |
Claims
1. A compression device for a limb of a patient comprising: i. an
inflatable sleeve arranged to surround the limb; ii. a conduit
attached to the sleeve arranged to deliver fluid to the sleeve;
iii. a control system arranged to control flow of fluid in the
device; and iv. a memory arranged to store gathered data relating
to use of the device.
2. The compression device as claimed in claim 1, wherein the
control system comprises a pump and a controller unit.
3. The compression device as claimed in claim 1, further comprising
a display device arranged to provide a display dependent on the
gathered data.
4. The compression device as claimed in claim 1, wherein the memory
is arranged to store data relating to the duration of use of the
device.
5. The compression device as claimed in claim 1, wherein the memory
is arranged to store data relating to pressure exerted by the
sleeve on the limb.
6. The compression device as claimed in claim 1, wherein the memory
is arranged to store data relating to a mode of operation of the
device.
7. The compression device as claimed in claim 1, wherein the mode
of operation of the device selects a predetermined pressure profile
for the sleeve.
8. The compression device as claimed in claim 1, comprising one or
more pressure sensors arranged to determine when the pressure
exerted by the sleeve on the limb has reached a predetermined
value.
9. The compression device as claimed in claim 1, wherein the
inflatable sleeve includes one or more cells and each cell has an
associated pressure sensor arranged to determine the pressure
exerted by the cell.
10. The compression device as claimed in claim 8, wherein the one
or more pressure sensors each comprises a fluid pressure sensor
arranged to measure fluid pressure.
11. The compression device as claimed in claim 8, wherein the one
or more pressure sensors each comprises an air pressure sensor
arranged to measure the contact pressure between the sleeve and the
limb.
12. The compression device as claimed in claim 1, wherein the
compression device is arranged to detect whether the sleeve is in
place surrounding the limb.
13. The compression device according to claim 12, wherein the
gathered data is dependent upon detection of whether the sleeve is
in place surrounding the limb.
14. The compression device as claimed in claim 1, wherein expected
data values relating to use of the device are stored in the
memory.
15. The compression device as claimed in claim 14, wherein the
control system is arranged to compare gathered data with expected
data and thereby detect an error if the sleeve is not in place
surrounding the limb, if there is an error in the device or if
there is a puncture in the sleeve.
16. The compression device as claimed in claim 15, wherein the
control system is arranged to determine whether the sleeve
surrounds the limb by monitoring a change in pressure exerted by
the sleeve as it is inflated.
17. The compression device as claimed in claim 16, wherein the
control system is arranged to shut off delivery of fluid to the
sleeve if it is determined that the sleeve is not in place
surrounding the limb.
18. The compression device as claimed in claim 3 further comprising
user input means arranged to receive a user input to cause the
display dependent upon the gathered data to be displayed.
19. The compression device as claimed in claim 1, wherein the
compression device is for the limb of a mobile patient.
20. A method of monitoring use of a compression device for a limb
of a patient, said compression device comprising an inflatable
sleeve arranged to surround the limb: a conduit attached to the
sleeve arranged to deliver fluid to the sleeve; and a control
system arranged to control flow of fluid in the compression device,
comprising the step of storing gathered data relating to use of the
compression device.
21. The method of claim 20 further comprising the step of
displaying information relating to the gathered data.
22. The method of claim 20, wherein the step of storing gathered
data occurs with a data carrier carrying software which, when run
on a processor of a control system of the compression device, is
arranged to monitor use of the device.
23. A method of treating venous leg ulcers, venous insufficiency or
deep vein thrombosis comprising applying a compression device to a
limb of a patient, said compression device comprising an inflatable
sleeve arranged to surround the limb; a conduit attached to the
sleeve arranged to deliver fluid to the sleeve; and a control
system arranged to control the flow of fluid in the compression
device, gathering data relating to use of the compression device,
and storing the data in a memory.
Description
[0001] This invention relates to a compression device for the limb
and particularly to a device for use on the leg. For example, the
device may be used for compression therapy used in the treatment of
venous leg ulcers.
BACKGROUND OF THE INVENTION
[0002] Various compression devices are known for applying
compressive pressure to a patient's limb. These types of devices
are used to assist mainly in the prevention of deep vein thrombosis
(DVT), vascular disorders and the reduction of oedema. U.S. Patent
Application No. 2004/0111 048 (Jensen, et al.) and U.S. Pat. No.
6,786,879 (KCI Licensing Inc.) disclose such devices.
[0003] Compression therapy is used in the treatment of venous leg
ulcers. The treatment relies on the compression achieving a
reduction in oedema and improved return of blood via the venous
system. This, in turn, reduces the residence time for blood
supplied to the lower limb and the severity of ischaemic episodes
within the limb that can result in tissue breakdown.
[0004] Compression of the limb in the treatment of venous leg
ulcers is most usually achieved by the use of elastic bandages.
Elastic bandages have the advantages that the patient can be
mobile; can be treated at home; and that once applied by a health
care professional, any removal or interference may be possible to
detect. Elastic bandages do, however, have many disadvantages: they
can work loose; the pressure generated by the bandage on the limb
is not measured and depends on the level of skill of the health
care professional applying the bandage; the level of compression is
also affected by the circumference of the limb; the bandage cannot
be removed and reapplied by the patient, for instance, for bathing;
and many patients find them unsightly, uncomfortable, hot or
painful.
[0005] Compression of the limb in the treatment of venous leg
ulcers can also be achieved by the use of compression stockings,
although they are most often used in the prevention of leg ulcers,
for instance, in the prevention of recurrence after an active leg
ulcer has healed. Compression stockings have many of the advantages
of elastic bandages: they can be used at home and the patient can
be mobile. They, however, have some disadvantages; they are
difficult to apply as the narrow ankle part has to be pulled over
the heel; compliance with treatment is difficult to monitor as the
patient may be able to remove and replace the stocking themselves;
and patients can find them uncomfortable.
[0006] Compression of the limb can also be achieved by a pneumatic
compression device. As venous leg ulcers are most usually treated
at home or in the community and the known compression devices are
large, heavy and require professional supervision, their adoption
for such treatment has not been widespread. The known devices, used
previously, apply pressure to the limb through a thick cuff or
cuffs which affect patient mobility and are aesthetically
unacceptable to many patients. The pump which produces the
compression is large and heavy and can supply fluid to the cuffs
through many pipes. These characteristics make the known devices
unsuitable for domestic use.
SUMMARY OF THE INVENTION
[0007] We have developed a pneumatic compression device more
suitable for home use.
[0008] Pneumatic compression devices have the following advantages:
they provide an effective treatment; while deflated, the inflatable
cuff or cuffs are easy to apply to the patient's leg; and the
pressure is more readily controlled and monitored.
[0009] However, as with all of the previously referenced devices,
compliance with treatment can be a problem as a patient treated at
home or in the community may remove the device, for any of the
reasons mentioned, which can result in insufficient usage of the
device and failure to follow a compression therapy schedule
prescribed by a healthcare professional. This can lead to a longer
healing time for the patient.
[0010] The present invention provides for a compression device for
a limb of a patient comprising: an inflatable sleeve arranged to
surround the limb, a conduit attached to the sleeve arranged to
deliver fluid to the sleeve, a control system arranged to control
flow of fluid in the device and a memory arranged to store gathered
data relating to use of the device.
[0011] Advantageously, such a compression device allows direct
monitoring of use of the device by, for example, a healthcare
professional. A patient may only see a healthcare professional once
or twice a week and this device provides the healthcare
professional with independent knowledge of the usage details which
the patient may otherwise be reluctant to provide or may not be
able to provide accurately. Problems associated with cases of poor
usage of the compression device can thus be more easily
identified.
[0012] The control system comprises a pump and a controller unit.
The control system, further comprises a display device arranged to
provide a display dependent upon the gathered data. Preferably, the
controller unit is portable and wearable and, more preferably, it
is attached to the conduit. The controller unit includes a display
which may be in the form of a liquid crystal display (LCD) or other
similar type display. Alternatively, the display may be part of a
remote device such as a personal computer with which the controller
can communicate, e.g., by cable connection, radio frequency,
infrared or other similar means of communication.
[0013] The compression device comprises at least one pressure
sensor arranged to measure the pressure exerted by the compression
device. The sensor or sensors are attached to the sleeve and
located between the sleeve and the limb, the sensor(s) provide
readings of the pressure experienced by the limb due to the
inflation of the sleeve by the controller. The pressure sensor may
be a contact pressure sensor or other similar type sensor.
[0014] We have found that monitoring the actual pressure
experienced by the limb due to the compression device enables the
compression device to provide a predetermined compression profile
to the limb. The predetermined compression profile is selected by
the health care professional to cater for the patient's condition.
For example, a patient with lymphodema may require a different
level of compression than a patient with a healed leg ulcer. The
sensor also allows the compression device to increase or decrease
the pressure on a particular part of the limb to give the
predetermined compression profile while the compression device is
in use. This alleviates the problem of pressure difference
experienced with the use of elastic bandages where the pressure
depends on the tension in the bandage, the amount of overlap and
the shape of the leg of the patient.
[0015] The pressure sensor is used to measure the fluid pressure
inside the sleeve, thus providing a measure of the pressure exerted
by the sleeve. The sleeve has a valve associated with it and the
control system is arranged to control operation of the valve and,
thereby, inflation/deflation of the sleeve. The pressure sensors
associated with the sleeve are, preferably, located between the
valve and the sleeve. The pressure sensor is, preferably, a fluid
pressure sensor arranged to measure fluid pressure preferably in
the line between the valve and sleeve.
[0016] The sleeve comprises one or more individually inflatable
cells. Preferably, a sensor is associated with each cell to monitor
the pressure experienced by the limb due to pressure from that
cell. For example, each sleeve may have a valve associated with it
and the controller is arranged to control operation of the valve
and, therefore, inflation/deflation of each cell. The pressure
sensors associated with each cell are, preferably, located between
the valve and the cell. This allows the compression device to
precisely control the pressure in each cell and, thus, comply with
the predetermined compression profile. It also allows the
compression device to operate an intermittent pneumatic
compression.
[0017] The memory is arranged to store data relating to any one or
more of: the duration of use of the compression device, the
pressure exerted by the sleeve on the limb and the mode of
operation of the device. The memory is also arranged to store data
relating to the use of the compression device while it is in place
surrounding the limb. To accomplish this, the control system must
first determine whether or not the device is in place surrounding
the limb. This may be achieved by having expected data values
relating to use of the device stored in the memory for comparison
by the control system with gathered data values. For example, when
the sleeve is in place on the limb it will have a different
inflation profile compared to when it is not in place surrounding
the limb. The control system may monitor a change in pressure
exerted by the sleeve as it is inflated, e.g., by monitoring the
time taken to inflate the sleeve to a predetermined pressure, and
this will vary depending upon whether or not the device is in place
surrounding a limb. Therefore, by comparing gathered data with
expected time and pressure data values, the controller can
determine whether or not the sleeve is in place surrounding the
limb.
[0018] Advantageously, the control system may be arranged to
disregard any data gathered when the sleeve is not in place around
the limb and this provides more accurate, useful gathered data for
analysis.
[0019] Preferably, when the sleeve is not in place surrounding the
limb, the control system is arranged to shut off delivery of fluid
through the sleeve and preferably deflate the sleeve.
Advantageously, this provides a safety mechanism against
unnecessary inflation or over-inflation of the inflatable sleeve
when it is not in place surrounding the limb.
[0020] Due to the sensors and monitoring capacity of the
compression device, and the microprocessor present in the control
system, it is possible to monitor the usage of the compression
device by the patient. This is not possible with elastic
compression devices. Knowledge of the extent of usage enables the
health care professional to prescribe the most suitable treatment
for the next stage of healing or prevention.
[0021] The capability of the controller to deliver predetermined
compression profiles to the limb also enables the health care
professional to give the patient some control over his or her
treatment. For a chosen treatment regime, the patient can select a
high compression or low compression setting. This alleviates the
problem of non-compliance in some patients who cannot tolerate the
pain of compression bandages or stockings that only provide one
compression level. The use of the device on a low setting is
preferable to rejection of the treatment altogether.
[0022] The compression device may be used for the limb of a mobile
patient.
[0023] Preferably, the sleeve is low profile and discrete, allowing
the patient to use the device while wearing ordinary clothes and
shoes.
[0024] Preferably, the sleeve comprises a leg cuff and a foot cuff
both of which are low profile and discrete. Preferably, the leg and
foot cuffs are anatomically shaped to provide compression on those
parts of the leg or foot which have the greatest effect on blood
flow. This provides the advantage of reducing the overall size of
the device and, thus, the profile of the cuff and size and power of
the pump. Depending on the shape of the cuffs, it can also reduce
discomfort from pressure on bony areas of the limb.
[0025] Another aspect of the present invention, provides a method
of monitoring use of a compression device for a limb of a patient
having an inflatable sleeve arranged to surround the limb, a
conduit attached to the sleeve arranged to deliver fluid to the
sleeve and a control system arranged to control flow of fluid in
the device including the step of storing gathered data relating to
use of the device.
[0026] Still another aspect of the present invention provides a
data carrier carrying software which, when run on a processor of a
control system of a compression device, is arranged to monitor use
of the compression device according to the method of the second
embodiment of the invention.
BRIEF DESCRIPTION OF THE DRAWING
[0027] FIG. 1 is a perspective view of the sleeve of a first
embodiment of the device on the limb and the controller.
[0028] FIG. 2 is a perspective view of the sleeve of the device off
the limb and opened up.
[0029] FIG. 3 is a schematic diagram of the functional units of the
control system of the device.
[0030] FIG. 4 is a perspective view of the sleeve and controller of
a second embodiment of the device on the limb.
[0031] FIGS. 5a to 5c are schematic diagrams of a pump and valve
arrangement of the device of FIG. 4.
DETAILED DESCRIPTION OF THE INVENTION
[0032] In FIG. 1 the compression device of the invention is shown
on the leg of a patient in a standing position. The compression
device comprises a sleeve 2 having a leg cuff 4 connected to a foot
cuff 6. The compression device also comprises a control system
housed within a controller unit 8. The sleeve 2 is connected to the
controller unit 8 by a conduit 10. The controller unit 8 is a
small, hand held unit that may be clipped to the sleeve 2 or to the
waistband of the patient's trousers or skirt. The controller unit 8
is battery powered, e.g., by a Lithium battery, and rechargeable so
that it can be recharged on a base unit 12. The compression device
also comprises an understocking 14 worn between the patient's leg
and the sleeve 2. The understocking 14 is present to absorb any
moisture from the patient's leg but is not intended to apply
compression. The sleeve 2 has an inner surface 16 and an outer
surface 18 composed of a durable flexible material that can be
sponged clean and is divided into a plurality of cells 20 best seen
in FIG. 2.
[0033] The controller unit 8 comprises a display 21, e.g., in the
form of an LCD panel. Additionally, the controller unit 8 comprises
a user input 26, e.g., in the form of a row of buttons. Referring
to FIG. 3, the controller unit 8 comprises a microprocessor 28, and
a memory 30. The control system also comprises a pump and valve
arrangement 32. A pressure sensor 34 is attached to the sleeve 2
and located between the sleeve 2 and the limb and provides readings
of the pressure experienced by the limb due to inflation of the
sleeve 2 by the control system. In this embodiment the pressure
sensor 34 is a contact pressure sensor. The microprocessor 28 is
able to read data from and write data to the memory. Operation of
the control system by a user is achieved via the user input 26.
[0034] In use, the pressure sensor 34 provides information relating
to the pressure exerted by the sleeve 2 on the limb. The
microprocessor 28 is able to determine the length of time the
sleeve 2 is inflated and in place surrounding the limb. This data
is stored in the memory 30. The compression device operates in a
continuous pressure mode. In this continuous pressure mode a
patient or healthcare professional uses the user input 26 to input
a desired constant pressure which is required to be applied to the
limb via the sleeve 2. The microprocessor 28 arranges for inflation
of the sleeve 2 to the required pressure. The pressure sensor 34 is
used to determine when the required pressure has been reached. If,
during the course of time, the pressure being exerted by the sleeve
2 on the limb falls below a required level, it is detected by the
pressure sensor 34 and the microprocessor 28 communicates with the
pump and valve arrangement 32 in order to inflate the sleeve 2 back
up to the required level of pressure.
[0035] The microprocessor 28 runs a timer program to measure the
length of time for which the pressure being applied by the sleeve 2
is at a particular level. This data is stored in the memory 30.
Using the user input 26, the user can specify the length of time
the sleeve should remain inflated. After this length of time has
expired, the microprocessor 28 arranges for deflation of the sleeve
2.
[0036] Using the user input 26, the healthcare professional can
request details of use of the device to be displayed on the display
21, by, for example, inputting a personal identification number
(PIN) or other code.
[0037] FIG. 4 shows a compression device according to a second
embodiment of the invention where the leg cuff 4 and foot cuff 6
comprise cells with an anatomical shape 22. Four cells are provided
in this embodiment. Each cell is provided with a sensor located
centrally in each cell, but on the inside of the sleeve 2 between
the sleeve 2 and the leg. In FIG. 4 the sleeve 2 is marked on the
outside at a position corresponding to the position of the sensor
in the inside of the sleeve 2 at 24. The foot cuff 6 in either
embodiment may have a sensor located in a position corresponding to
the instep of the foot.
[0038] Still referring to FIG. 4, the control system associated
with the compression device according to the second embodiment is
similar to the control system of the compression device according
to the first embodiment, except that there are four contact
pressure sensors instead of only one contact pressure sensor. There
is one pressure sensor associated with each cell of the sleeve 2.
Referring to FIGS. 5a to 5c, the pump and valve arrangement 32 of
the compression device of this embodiment includes six valves 36
and a pump 38 controlled by a microprocessor. The pump 38 has an
inlet I and an outlet 0 and, together with an inlet valve 36P1 and
an outlet valve 36P2, controls the air pressure in a fluid feed
line F. The other valves are cell valves 36C associated with each
cell and arranged to control the flow of air between the cells and
the fluid feed line F. The pump valves 36P1, 36P2 each have a port
connected to atmosphere and a port connected to the feed line F in
addition to a port connected to the pump inlet I or outlet O. The
pump valve 36P1 is able to connect the pump inlet I to the feed
line F or to atmosphere. The pump valve 36P2 is able to connect the
pump outlet O to the feed line F or to the atmosphere. The
microprocessor is able to provide instructions to the pump 38 and
pump valves and cell valves such that the pump 38 can be used to
selectively inflate or deflate any one or more of the cells. This
is achieved by selectively operating the pump valves 36P1, 36P2 to
control direction of air flow to or from the fluid feed line F and
controlling the cell valves 36C which are selectively opened or
closed to allow flow of air to and from the individual cells. For
each cell, the pressure sensors 34 are contact pressure sensors
located on the surface of the sleeve.
[0039] The pump 38 is typically non-reversible and operates to pump
air in a direction from its inlet I to its outlet O. Referring to
FIG. 5a, when it is desired to draw air from the cells, the pump
valve 36P1 is arranged to connect the pump inlet I to the fluid
feed line F by the microprocessor and the pump valve 36P2 is
arranged to connect the pump outlet O to atmosphere. This operation
of the valves 36P1, 36P2 causes the air within the pump 38 and
valve arrangement 32 to flow in the direction indicated by the
arrows of FIG. 5a. Therefore, air is pumped away from the cells.
Each one of the cell valves 36C can be operated individually under
instruction from the microprocessor so that air may be drawn from
one or more cells without being drawn from the other cells.
[0040] Referring to FIG. 5b, when it is desired to pump air to the
cells, the first pump valve 36P1 is arranged to connect the pump
inlet I to atmosphere and the second pump valve 36P2 is arranged to
connect the pump outlet O to the fluid feed line F. Operation of
the pump 38 then causes air to flow in the direction of the arrows
shown in FIG. 5b, i.e., air is pumped towards the cells. Once
again, the cell valves 36C can be individually operated by the
microprocessor so that any one or more cells may be pumped up
selectively.
[0041] Referring to FIG. 5c, when the cells are at a desired
pressure, e.g., after they have been pumped up sufficiently for use
in the continuous pressure mode, both pump valves 36P1 and 36P2 are
arranged to connect the pump 38 to atmosphere so that the fluid in
the fluid feed line F is at atmospheric pressure. The pump 38 does
not operate and the air pressure inside the cells remains
unchanged.
[0042] The compression device of the second embodiment is able to
be selectively operated in a different mode to that previously
described for the first embodiment. The compression device can also
be operated in the same mode as previously described. In its
different mode, the compression device can be used to provide
intermittent pneumatic compression in which each of the cells is
inflated in sequence, e.g., from the bottom of the leg upwards.
Compliance data, i.e., data relating to use of the compression
device, can be gathered by the microprocessor 28 (shown in FIG. 3)
and stored in the memory 30 (also shown in FIG. 3). Using the user
input 26, the healthcare professional can request that the gathered
data stored in the memory 30 is displayed upon the display 21. In
this embodiment, the display 21 is not part of the controller.
Instead, the controller unit can communicate, e.g., via infrared
communication, with a remote display screen (not shown). The
displayed data includes data relating to the length of time for
which each cell has been inflated while surrounding the limb at a
particular pressure and in a particular mode, e.g., continuous
constant pressure mode or intermittent pneumatic compression mode.
The displayed data can also include data relating to the number of
times which a patient has used the compression device within a set
period, e.g., within the last week, two weeks, or since the last
visit by the healthcare professional. The data can also include
data relating to the actual time of day at which the compression
device is used by a patient. The display data can also be analyzed
and a display provided to indicate whether or not the compliance by
the patient is good or bad. There may be a set threshold of use
above which the compliance is good and below which it is bad. The
displayed data which is available to the patient may be different
than displayed data which is available to the healthcare
professional--the healthcare professional may have access to more
information upon entry of a password, PIN or other code using the
user input 26.
[0043] Using the user input 26, it is possible for the healthcare
professional to reset some or all of the data stored in the memory
30. This can be desirable between the visits of a healthcare
professional to a patient for example. The healthcare professional
may be required to enter a password, PIN or other code using the
user input 26 before data stored in the memory 30 can be erased.
The memory 30 can also store data on the date of the last reset.
Thus, for instance, if the patient resets the memory, the date is
recorded and at next visit the healthcare professional is presented
with the reset date and the data collected since the reset.
[0044] A range of standard or expected inflation times are stored
on the memory 30. Therefore, if the sleeve 2 is inflated while not
in place on the limb, then the microprocessor 28 will recognize
this by comparing data gathered from the pressure sensors 34 with
data stored in the memory 30. For example, the time taken to reach
a predetermined pressure value can be measured and, if it does not
fall within an expected range, then the microprocessor 28
recognizes that the sleeve 2 is not in place on the limb and causes
the pump and valve arrangement 32 to cease inflating the sleeve 2
and to deflate it instead. Data gathered by the sensors 34 whilst
the sleeve 2 is not in place on the limb can also be discarded. The
microprocessor can, therefore, determine, when the sleeve 2 is
inflated, whether it is in place on the patient's limb or not. This
ensures that data collected and stored relating to use of the
compression device can accurately reflect correct use of the
compression device when it is in place, and not be affected by
inflation of the sleeve when the device is not in place on the
patient.
[0045] Similarly a microprocessor 28 can recognize if the pump and
valve arrangement 32 is attempting to inflate the sleeve 2, but the
pressure measured by one or more of the pressure sensors 34 is not
increasing correspondingly. In this situation, the microprocessor
28 recognizes that the sleeve 2 has a puncture and a suitable error
message can be displayed on the display 21 to inform the user that
there is a puncture in said one or more of the cells 22.
[0046] Although the present invention has been shown and described
with respect to several preferred embodiments thereof, various
changes, omissions and additions to the form and detail thereof,
may be made therein, without departing from the scope of the
invention. For example, the data relating to use may be available
to any user without requiring entry of a PIN code. However, it may
still be necessary to input a password, PIN, or other code before
erasing information.
[0047] The intermittent pneumatic compression mode may be
selectively available with a device substantially identical to the
device of the first embodiment. Also the, or each, sensor may be a
contact sensor, a pressure sensor or any other suitable type of
sensor. Where more than one sensor is provided, combinations of
different types of sensor may be used. For example, the contact
pressure sensors of the second embodiment may be replaced by air
pressure sensors located in the line between the cell and its
associated valve 36. The sensor may be situated in the controller
unit 8.
[0048] The controller unit 8 may not have a user input 26. Instead,
for example, the system may receive inputs from, e.g., a keyboard
of a personal computer or other processing device when it is in
communication (e.g., infra-red) with it.
* * * * *